A content providing system such as a content searching system or content recommending system automatically selects a content, which a user wants, from among numerous contents and provides the selected content to the user. In this case, the content providing system analyzes explicit information such as history of the user's use of contents, demographic information of the user, and content information of the content selected by the user and then provides the content to the user.
A conventional content providing system has an advantage of being able to quickly provide information which a user wants. However, the conventional content providing system uses only explicit information, and thus has a disadvantage of being unable to reflect the user's needs.
In this regard, Korean Patent No. 10-1536520 (entitled “Method and server for extracting topic and evaluating compatibility of the extracted topic”) discloses a method including extracting a noun from a document group according to classification information, calculating a weighting for the noun and extracting a keyword which is a word representing the document group, calculating a weighting for the extracted keyword and generating a cluster by clustering the keyword and relative word, and extracting a topic group in accordance with classification by combining similar clusters of the generated clusters, and a server using the same.